1. Technical Field
The present invention relates to a position calculation.
2. Related Art
As a positioning system using a positioning signal, a GPS (Global Positioning System) is known and used for a position calculation apparatus embedded in a mobile phone or a car navigation system. The GPS is configured such that position calculation processing is carried out, in which a three-dimensional coordinate value representing the position of the position calculation apparatus and clock errors are calculated on the basis of information about the positions of a plurality of GPS satellites or a pseudo distance from each GPS satellite to the position calculation apparatus.
In order to improve accuracy in position calculation, a technique has been suggested in which the position calculated by the GPS is corrected by using the measurement result of an inertial navigation sensor, such as an acceleration sensor or a gyro sensor, and then position calculation is carried out (for example, Japanese Patent Application No. JP-T-2003-509671).
However, as described in Japanese Patent Application No. JP-T-2003-509671, the position calculation apparatus of the related art supposes that the GPS receiving circuit and various sensors are mounted therein. The position calculation apparatus carries out predetermined arithmetic processing by using the measurement results of the GPS receiving circuit and various sensors. For this reason, the position calculation apparatus may lack flexibility regarding expansion or change of the apparatus.